Apparatus for smelting iron ore.



No. 815,293. v PATENTEDMAR.13,1906.

P. L. T. HEROULT.

APPARATUS FOR SMELTING' IRON ORE.

APPLIOATION FILED SEPT. 7,1905.

INVENTOR: WITNESSES: K Zzdfw JMW/ WM, fl w M By fw'mj s,

UNITED STATES PATENT ()FFICE.

PAUL Lou s roUssAin'r HEROULT, or LA PRAZ, FRANCE, ASSIGNOR TO socncrn ELEo'rRO-ME' .ALLUnoioon FRANCAISE, OF rROeEs, isnnn, FRANCE,- A CORPORATION or rnAtnon.

APPARATUS FOR SMELTING IRON ORE.

Specification of Letters Patent.

Patented March 13, 1906.

Original application filed June 14, 1906, Serial No. 265,174. Divided and this application filed September 7, 1905- Serial No. 277,466.

residing at La Praz, Savoie, France, have invented certain new and useful Improvements in Apparatus for Sinelting Iron Ore or the Like, of which the following is a speci'hcation. I

This invention aims to rovide an. im- P e proved apparatus for the smelting of iron ores to make pig iron, the particular aim of the invention being to increase the caloricelficiency of the carbon used in the smelting.

In previous processes the ore has been intro. ducedat the top of the furnace mixed with carbon. At the base or the furnace, where the greatest heat has been and the greatest chemical activity, carbon monoxid and car bon dioxid have been formed in varying proportions. The mixture of gases passing up through the charge has then done very little to reduce the ore, the carbon mixed throughout the charge gradually increasing the percentage of carbon monoxid, so that the gases escaping at the top have been largely of arbon monoxid. Thus the carbon mixed throughout the charge has been largely burned to produce a gas having a high potential heat energy, and this heat energy has been lost to the furnace and only utilized in external apparatus to which the gas has been led.

The aim of the present invention is to in-- sure that the gas escaping at the top of the furnace shall be all or as much as )OSSllDlG carbon dioxidthat is to say, all t. e heat units developed by the carbon shall be developed within the furnace. The carbon is consumed only in the smelting-chamber, being protected by its manner or point of intro duction from the CO, generated in the smelt-- ing operation. The consequence is large reduction. in the quantity of necessary to be fed to the furnace.

In the preferred form of the apparatus the carbon may be introduced at the base of the charge and the latter led into the top of the furnace without admixture of carboi'i. Thus a mixture of carbon monoxid and carbon dioxid will be formed at the base of-the l'urnace and as this mixture of gases passes upward through the charge there will be no further carbon a very .two hundred and fifty calories gases.

wnsumption or carbon, but a further reduc-.

tion of the iron ore and a conversion of art of the carbon inonoxid into dioxid. J t a certain height above the point of formation of the monoxid, however, the mixture of gases is so diluted with carbon dioxid as to have substantially no further reducing efiect. At this point, as nearly as it can be determined, means are referably provided for supplying additiona oxygen to the ascending gases, and all or at least a great part of the remaining monoxid will be converted into dioxid, the heat produced by the combination serving to heat the charge above. Preferably the heat necessary for melting the iron is supplied by the electric current, so that only so much carbon will be needed as is necessary for ellecting the reduction of the ore.

The higher the point at which the injection of Oxygen (preferably in the "form of air) takes place the greater will be the utilization of the reducing power of the carbon monoxid, though such reducing power is a diminishing quantity. The lower the injection the greater the heat developed and the less the reduction of ore. The,most efilcient point can be readily determined by ex eriment for each particular case, it being on y necessary to avoid introducing the oxygen at so low a point as to make the ore above pasty.

As an illustration olthe economy which may be ell'ected by this apparatus, take one kilo of iron to be reduced from the ore, (l? 'The reduction requires about six teen hundred and. forty calories. To obtain this quantity of heat, it is necessary to burn only two hundred grains of carbon'to the dioxid, (C0,) in addition the o eration requires sullirient heat to melt t .e iron and slag, or for one kilo of iron twp l'iundred and fifty calories and for mic-half a kilo of slag a totalof five hundred calories. Two hundred grams of carbon and one horse-power (six hundred and thirtyealorics) will therefore effect the re duction and melting and provide an excessof one hundred and thirty calories for losses by radiation and the heat escaping With the with the ordinary process, where one kilo of carbon is used in producing one kilo of iron, is

The economyof this as compared very great. If instead of an electric furnace an ordinary furnace be emploed, heated by carbon injected at the base, t ere will be required about three hundred grams of carbon in place of the one horse-power in the above example in order to melt the iron and slag. The carbonmay be introduced in any suitable formsuch, for example, as a pulverized solid or a li uid or a gas-and either pure or mixed wit 1 other elements.

The accompanying drawings illustrate'a furnace embodying the invention.

Figure 1 of the drawings is a central vertical section. Fig. 2 is a cross-section on the line 2 2 of Fig. 1.

Referring to the s ecific form illustrated, the furnace is provi ed with an open upper end to permit the introduction of'the ore at The oxygen of the charge an with a the top and with tap-holes A A for withdrawing the iron and. slag at the bottom.

Provision is made for introducing the carbon at the bottom by the use of a hollow electrode B, through which pulverized carbon is forced down by means of a screw C,- driven from a motor D.

The provision for introducing oxygen com-- prises nozzles E, 1 passing through the wall F and preferably 0 the shape shownin Fig. 2, with orifices G extending downward and protected from entrance of ore by an overhanging portion H, the nozzle being also )rovided with a t. ered upper edge J to divide the ower inclined portion K for strength.

The electrode B is provided with an iron shell L, which burns away at the lower end, but which protects the electrode above the lower end from being eaten away by the carbon dioxid rising through the charge.

With this furnace the chargeM of ore is introduced at the top and gradually moves downward and contains substantially no mixture of carbon. The carbon N is all introduced through the hollow protected electrode, preferably in pulverized form, and forms at the base a sort of mushroom 0., surrounding the lower end of the electrode,and serving, in fact, the working electrode. The molten metal P collects at the bottom and is drawn off from time to time through the tap-hole A, as usual. The molten slag Q floats on the top of the molten metal P and shades gradually into thcsolid charge above. ore is extracted by com bining with the carbon, while the iron is melted and trickles in drops through the lower part of the charge and the slag to the pool beneath. The carbon monoxid and dioxid formed with the oxygen of the ore then pass upwardthrough the ore, taking ox *gen therefrom in graduallydiminishing uantities. There being no carbon )resent in t 1e charge, there is no reduction of t e dioxid to monoxid, such as takes place in the ordinary furnaces at present generally used. 011 the contrary, I

.maining monoxid is burned the full reducing effect of the monoxid is obtained, and when the mixture of gases is no longer strong enough to extract any substantial part of the oxygen from the ore the reby the oxygen entering through the nozzles E and develops a largequantit of heat, which heats the portion of the charge above the nozzles, and therefore renders the furnace as a whole more economical. The oxygen in the form of pure oxygen, air, or any gas containing oxygen may be forced into the nozzles E through a ring R, surrounding the nozzles.

This a plication is a division-of cation, erial No. 265,174, filed 1905, in which I have herein described.

Though I have described with I ticularity of detail certain embodiments of this invention, yet it is not to be understood my appli- June 14, claimed the process great par-' therefrom that the invention is limited to the specific embodiments disclosed.

Various modifications may be made by those skilled in the art from the invention.

What I claim is 1. A furnace for smelting iron or similar ores, having rovisions for admitting; the introduction o the ore at the top, andifor the protection of the carbon from the carbon dioxld generated in the smelting operation,- whereby a mixture of carbon monoxid and carbon dioxid is formed and rises through the mass, and having also provisions for introducing oxygen at a point above the point of formation of the carbon monoxid to con vert the carbon monoxid risin through the charge into carbon dioxid and increase the heating effect in the furnace.

2. A furnace for smelting iron or similar ores, having provisions for introducing the ore at the top for the protection of the carbon from the carbon clioxid generated in the smelting operation, and provided also with means for supplying the necessary heat by means of the electric current, and having also provisions for introducing oxygen at a point above the point of formation of the carbonmonoxid to convert the carbon monoxid rising through the charge into carbon dioxid and increase the heating effect in the furnace.

3. A furnace-for smelting iron or similar ores, having )rovisions for admitting the introduction of the ore at the top, and for the without departure protection of the carbon from the carbon digen through said nozzles to convert the can bon monoxid rising through the charge into carbon dioxid so as to increase the heating effeet in the furnace.

4. A furnace for smelting iron or similar 1 ores, having provisions for introducing the ore at the top and for the protection of. the

carbon from the carbon dioxid generated in the smelting Operation, and provided also,

with means for supplying the necessary heat-by means of the electric current, noz+ z les projecting within the walls of the furnace, and 1'I16&I1S \for introducing oxygen through said nozzles to convert the carbon 1o monoxid through the charge into carbondioxid to increase the heating effect of the furnace. y In witness whereof I have hereunto signed my name ln-the presence of two subscribing witnesses.

PAUL LOUIS moUssmr HEROUhT..

Witnesses: v

' Dommeo A. USINA, THEODORE T. SNELn. 

